1 ;;;; This file contains the LTN pass in the compiler. LTN allocates
2 ;;;; expression evaluation TNs, makes nearly all the implementation
3 ;;;; policy decisions, and also does a few other miscellaneous things.
5 ;;;; This software is part of the SBCL system. See the README file for
8 ;;;; This software is derived from the CMU CL system, which was
9 ;;;; written at Carnegie Mellon University and released into the
10 ;;;; public domain. The software is in the public domain and is
11 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
12 ;;;; files for more information.
18 ;;; Return the LTN-POLICY indicated by the node policy.
20 ;;; FIXME: It would be tidier to use an LTN-POLICY object (an instance
21 ;;; of DEFSTRUCT LTN-POLICY) instead of a keyword, and have queries
22 ;;; like LTN-POLICY-SAFE-P become slot accessors. If we do this,
23 ;;; grep for and carefully review use of literal keywords, so that
25 ;;; (EQ (TEMPLATE-LTN-POLICY TEMPLATE) :SAFE)
26 ;;; don't get overlooked.
28 ;;; FIXME: Classic CMU CL went to some trouble to cache LTN-POLICY
29 ;;; values in LTN-ANALYZE so that they didn't have to be recomputed on
30 ;;; every block. I stripped that out (the whole DEFMACRO FROB thing)
31 ;;; because I found it too confusing. Thus, it might be that the
32 ;;; new uncached code spends an unreasonable amount of time in
33 ;;; this lookup function. This function should be profiled, and if
34 ;;; it's a significant contributor to runtime, we can cache it in
35 ;;; some more local way, e.g. by adding a CACHED-LTN-POLICY slot to
36 ;;; the NODE structure, and doing something like
37 ;;; (DEFUN NODE-LTN-POLICY (NODE)
38 ;;; (OR (NODE-CACHED-LTN-POLICY NODE)
39 ;;; (SETF (NODE-CACHED-LTN-POLICY NODE)
40 ;;; (NODE-UNCACHED-LTN-POLICY NODE)))
41 (defun node-ltn-policy (node)
42 (declare (type node node
))
44 (let ((eff-space (max space
45 ;; on the theory that if the code is
46 ;; smaller, it will take less time to
47 ;; compile (could lose if the smallest
48 ;; case is out of line, and must
49 ;; allocate many linkage registers):
52 (if (>= speed eff-space
) :fast
:small
)
53 (if (>= speed eff-space
) :fast-safe
:safe
)))))
55 ;;; Return true if LTN-POLICY is a safe policy.
56 (defun ltn-policy-safe-p (ltn-policy)
58 ((:safe
:fast-safe
) t
)
59 ((:small
:fast
) nil
)))
61 ;;; an annotated lvar's primitive-type
62 #!-sb-fluid
(declaim (inline lvar-ptype
))
63 (defun lvar-ptype (lvar)
64 (declare (type lvar lvar
))
65 (ir2-lvar-primitive-type (lvar-info lvar
)))
67 ;;; Return true if a constant LEAF is of a type which we can legally
68 ;;; directly reference in code. Named constants with arbitrary pointer
69 ;;; values cannot, since we must preserve EQLness.
70 (defun legal-immediate-constant-p (leaf)
71 (declare (type constant leaf
))
72 (or (not (leaf-has-source-name-p leaf
))
73 (typecase (constant-value leaf
)
74 ((or number character
) t
)
75 (symbol (symbol-package (constant-value leaf
)))
78 ;;; If LVAR is used only by a REF to a leaf that can be delayed, then
79 ;;; return the leaf, otherwise return NIL.
80 (defun lvar-delayed-leaf (lvar)
81 (declare (type lvar lvar
))
82 (let ((use (lvar-uses lvar
)))
84 (let ((leaf (ref-leaf use
)))
86 (lambda-var (if (null (lambda-var-sets leaf
)) leaf nil
))
87 (constant (if (legal-immediate-constant-p leaf
) leaf nil
))
88 ((or functional global-var
) nil
))))))
90 ;;; Annotate a normal single-value lvar. If its only use is a ref that
91 ;;; we are allowed to delay the evaluation of, then we mark the lvar
92 ;;; for delayed evaluation, otherwise we assign a TN to hold the
94 (defun annotate-1-value-lvar (lvar)
95 (declare (type lvar lvar
))
96 (let ((info (lvar-info lvar
)))
97 (aver (eq (ir2-lvar-kind info
) :fixed
))
99 ((lvar-delayed-leaf lvar
)
100 (setf (ir2-lvar-kind info
) :delayed
))
101 (t (setf (ir2-lvar-locs info
)
102 (list (make-normal-tn (ir2-lvar-primitive-type info
)))))))
103 (ltn-annotate-casts lvar
)
106 ;;; Make an IR2-LVAR corresponding to the lvar type and then do
107 ;;; ANNOTATE-1-VALUE-LVAR.
108 (defun annotate-ordinary-lvar (lvar)
109 (declare (type lvar lvar
))
110 (let ((info (make-ir2-lvar
111 (primitive-type (lvar-type lvar
)))))
112 (setf (lvar-info lvar
) info
)
113 (annotate-1-value-lvar lvar
))
116 ;;; Annotate the function lvar for a full call. If the only reference
117 ;;; is to a global function and DELAY is true, then we delay the
118 ;;; reference, otherwise we annotate for a single value.
119 (defun annotate-fun-lvar (lvar &optional
(delay t
))
120 (declare (type lvar lvar
))
121 (let* ((tn-ptype (primitive-type (lvar-type lvar
)))
122 (info (make-ir2-lvar tn-ptype
)))
123 (setf (lvar-info lvar
) info
)
124 (let ((name (lvar-fun-name lvar t
)))
126 (setf (ir2-lvar-kind info
) :delayed
)
127 (setf (ir2-lvar-locs info
)
128 (list (make-normal-tn tn-ptype
))))))
129 (ltn-annotate-casts lvar
)
132 ;;; If TAIL-P is true, then we check to see whether the call can
133 ;;; really be a tail call by seeing if this function's return
134 ;;; convention is :UNKNOWN. If so, we move the call block successor
135 ;;; link from the return block to the component tail (after ensuring
136 ;;; that they are in separate blocks.) This allows the return to be
137 ;;; deleted when there are no non-tail uses.
138 (defun flush-full-call-tail-transfer (call)
139 (declare (type basic-combination call
))
140 (let ((tails (and (node-tail-p call
)
141 (lambda-tail-set (node-home-lambda call
)))))
143 (cond ((eq (return-info-kind (tail-set-info tails
)) :unknown
)
144 (node-ends-block call
)
145 (let ((block (node-block call
)))
146 (unlink-blocks block
(first (block-succ block
)))
147 (link-blocks block
(component-tail (block-component block
)))))
149 (setf (node-tail-p call
) nil
)))))
152 ;;; We set the kind to :FULL or :FUNNY, depending on whether there is
153 ;;; an IR2-CONVERT method. If a funny function, then we inhibit tail
154 ;;; recursion normally, since the IR2 convert method is going to want
155 ;;; to deliver values normally. We still annotate the function lvar,
156 ;;; since IR2tran might decide to call after all.
158 ;;; Note that args may already be annotated because template selection
159 ;;; can bail out to here.
160 (defun ltn-default-call (call)
161 (declare (type combination call
))
162 (let ((kind (basic-combination-kind call
)))
163 (annotate-fun-lvar (basic-combination-fun call
))
165 (dolist (arg (basic-combination-args call
))
166 (unless (lvar-info arg
)
167 (setf (lvar-info arg
)
168 (make-ir2-lvar (primitive-type (lvar-type arg
)))))
169 (annotate-1-value-lvar arg
))
172 ((and (fun-info-p kind
)
173 (fun-info-ir2-convert kind
))
174 (setf (basic-combination-info call
) :funny
)
175 (setf (node-tail-p call
) nil
))
177 (when (eq kind
:error
)
178 (setf (basic-combination-kind call
) :full
))
179 (setf (basic-combination-info call
) :full
)
180 (flush-full-call-tail-transfer call
))))
184 ;;; Annotate an lvar for unknown multiple values:
185 ;;; -- Add the lvar to the IR2-BLOCK-POPPED if it is used across a
187 ;;; -- Assign an :UNKNOWN IR2-LVAR.
189 ;;; Note: it is critical that this be called only during LTN analysis
190 ;;; of LVAR's DEST, and called in the order that the lvarss are
191 ;;; received. Otherwise the IR2-BLOCK-POPPED and
192 ;;; IR2-COMPONENT-VALUES-FOO would get all messed up.
193 (defun annotate-unknown-values-lvar (lvar)
194 (declare (type lvar lvar
))
196 (let ((2lvar (make-ir2-lvar nil
)))
197 (setf (ir2-lvar-kind 2lvar
) :unknown
)
198 (setf (ir2-lvar-locs 2lvar
) (make-unknown-values-locations))
199 (setf (lvar-info lvar
) 2lvar
))
201 ;; The CAST chain with corresponding lvars constitute the same
202 ;; "principal lvar", so we must preserve only inner annotation order
203 ;; and the order of the whole p.l. with other lvars. -- APD,
205 (ltn-annotate-casts lvar
)
207 (let* ((block (node-block (lvar-dest lvar
)))
208 (use (lvar-uses lvar
))
209 (2block (block-info block
)))
210 (unless (and (not (listp use
)) (eq (node-block use
) block
))
211 (setf (ir2-block-popped 2block
)
212 (nconc (ir2-block-popped 2block
) (list lvar
)))))
216 ;;; Annotate LVAR for a fixed, but arbitrary number of values, of the
217 ;;; specified primitive TYPES.
218 (defun annotate-fixed-values-lvar (lvar types
)
219 (declare (type lvar lvar
) (list types
))
220 (let ((res (make-ir2-lvar nil
)))
221 (setf (ir2-lvar-locs res
) (mapcar #'make-normal-tn types
))
222 (setf (lvar-info lvar
) res
))
223 (ltn-annotate-casts lvar
)
226 ;;;; node-specific analysis functions
228 ;;; Annotate the result lvar for a function. We use the RETURN-INFO
229 ;;; computed by GTN to determine how to represent the return values
230 ;;; within the function:
231 ;;; * If the TAIL-SET has a fixed values count, then use that many
233 ;;; * If the actual uses of the result lvar in this function
234 ;;; have a fixed number of values (after intersection with the
235 ;;; assertion), then use that number. We throw out TAIL-P :FULL
236 ;;; and :LOCAL calls, since we know they will truly end up as TR
237 ;;; calls. We can use the BASIC-COMBINATION-INFO even though it
238 ;;; is assigned by this phase, since the initial value NIL doesn't
239 ;;; look like a TR call.
240 ;;; If there are *no* non-tail-call uses, then it falls out
241 ;;; that we annotate for one value (type is NIL), but the return
242 ;;; will end up being deleted.
243 ;;; In non-perverse code, the DFO walk will reach all uses of the
244 ;;; result lvar before it reaches the RETURN. In perverse code, we
245 ;;; may annotate for unknown values when we didn't have to.
246 ;;; * Otherwise, we must annotate the lvar for unknown values.
247 (defun ltn-analyze-return (node)
248 (declare (type creturn node
))
249 (let* ((lvar (return-result node
))
250 (fun (return-lambda node
))
251 (returns (tail-set-info (lambda-tail-set fun
)))
252 (types (return-info-types returns
)))
253 (if (eq (return-info-count returns
) :unknown
)
254 (collect ((res *empty-type
* values-type-union
))
255 (do-uses (use (return-result node
))
256 (unless (and (node-tail-p use
)
257 (basic-combination-p use
)
258 (member (basic-combination-info use
) '(:local
:full
)))
259 (res (node-derived-type use
))))
262 (multiple-value-bind (types kind
)
263 (if (eq int
*empty-type
*)
264 (values nil
:unknown
)
266 (if (eq kind
:unknown
)
267 (annotate-unknown-values-lvar lvar
)
268 (annotate-fixed-values-lvar
269 lvar
(mapcar #'primitive-type types
))))))
270 (annotate-fixed-values-lvar lvar types
)))
274 ;;; Annotate the single argument lvar as a fixed-values lvar. We look
275 ;;; at the called lambda to determine number and type of return values
276 ;;; desired. It is assumed that only a function that
277 ;;; LOOKS-LIKE-AN-MV-BIND will be converted to a local call.
278 (defun ltn-analyze-mv-bind (call)
279 (declare (type mv-combination call
))
280 (setf (basic-combination-kind call
) :local
)
281 (setf (node-tail-p call
) nil
)
282 (annotate-fixed-values-lvar
283 (first (basic-combination-args call
))
284 (mapcar (lambda (var)
285 (primitive-type (basic-var-type var
)))
287 (ref-leaf (lvar-use (basic-combination-fun call
))))))
290 ;;; We force all the argument lvars to use the unknown values
291 ;;; convention. The lvars are annotated in reverse order, since the
292 ;;; last argument is on top, thus must be popped first. We disallow
293 ;;; delayed evaluation of the function lvar to simplify IR2 conversion
296 ;;; We could be cleverer when we know the number of values returned by
297 ;;; the lvars, but optimizations of MV call are probably unworthwhile.
299 ;;; We are also responsible for handling THROW, which is represented
300 ;;; in IR1 as an MV call to the %THROW funny function. We annotate the
301 ;;; tag lvar for a single value and the values lvar for unknown
303 (defun ltn-analyze-mv-call (call)
304 (declare (type mv-combination call
))
305 (let ((fun (basic-combination-fun call
))
306 (args (basic-combination-args call
)))
307 (cond ((eq (lvar-fun-name fun
) '%throw
)
308 (setf (basic-combination-info call
) :funny
)
309 (annotate-ordinary-lvar (first args
))
310 (annotate-unknown-values-lvar (second args
))
311 (setf (node-tail-p call
) nil
))
313 (setf (basic-combination-info call
) :full
)
314 (annotate-fun-lvar (basic-combination-fun call
)
316 (dolist (arg (reverse args
))
317 (annotate-unknown-values-lvar arg
))
318 (flush-full-call-tail-transfer call
))))
322 ;;; Annotate the arguments as ordinary single-value lvars. And check
324 (defun ltn-analyze-local-call (call)
325 (declare (type combination call
))
326 (setf (basic-combination-info call
) :local
)
327 (dolist (arg (basic-combination-args call
))
329 (annotate-ordinary-lvar arg
)))
330 (when (node-tail-p call
)
331 (set-tail-local-call-successor call
))
334 ;;; Make sure that a tail local call is linked directly to the bind
335 ;;; node. Usually it will be, but calls from XEPs and calls that might have
336 ;;; needed a cleanup after them won't have been swung over yet, since we
337 ;;; weren't sure they would really be TR until now.
338 (defun set-tail-local-call-successor (call)
339 (let ((caller (node-home-lambda call
))
340 (callee (combination-lambda call
)))
341 (aver (eq (lambda-tail-set caller
)
342 (lambda-tail-set (lambda-home callee
))))
343 (node-ends-block call
)
344 (let ((block (node-block call
)))
345 (unlink-blocks block
(first (block-succ block
)))
346 (link-blocks block
(lambda-block callee
))))
349 ;;; Annotate the value lvar.
350 (defun ltn-analyze-set (node)
351 (declare (type cset node
))
352 (setf (node-tail-p node
) nil
)
353 (annotate-ordinary-lvar (set-value node
))
356 ;;; If the only use of the TEST lvar is a combination annotated with a
357 ;;; conditional template, then don't annotate the lvar so that IR2
358 ;;; conversion knows not to emit any code, otherwise annotate as an
359 ;;; ordinary lvar. Since we only use a conditional template if the
360 ;;; call immediately precedes the IF node in the same block, we know
361 ;;; that any predicate will already be annotated.
362 (defun ltn-analyze-if (node)
363 (declare (type cif node
))
364 (setf (node-tail-p node
) nil
)
365 (let* ((test (if-test node
))
366 (use (lvar-uses test
)))
367 (unless (and (combination-p use
)
368 (let ((info (basic-combination-info use
)))
369 (and (template-p info
)
370 (eq (template-result-types info
) :conditional
))))
371 (annotate-ordinary-lvar test
)))
374 ;;; If there is a value lvar, then annotate it for unknown values. In
375 ;;; this case, the exit is non-local, since all other exits are
376 ;;; deleted or degenerate by this point.
377 (defun ltn-analyze-exit (node)
378 (setf (node-tail-p node
) nil
)
379 (let ((value (exit-value node
)))
381 (annotate-unknown-values-lvar value
)))
384 ;;; We need a special method for %UNWIND-PROTECT that ignores the
385 ;;; cleanup function. We don't annotate either arg, since we don't
386 ;;; need them at run-time.
388 ;;; (The default is o.k. for %CATCH, since environment analysis
389 ;;; converted the reference to the escape function into a constant
390 ;;; reference to the NLX-INFO.)
391 (defoptimizer (%unwind-protect ltn-annotate
) ((escape cleanup
)
394 ltn-policy
; a hack to effectively (DECLARE (IGNORE LTN-POLICY))
395 (setf (basic-combination-info node
) :funny
)
396 (setf (node-tail-p node
) nil
))
398 ;;;; known call annotation
400 ;;; Return true if RESTR is satisfied by TYPE. If T-OK is true, then a
401 ;;; T restriction allows any operand type. This is also called by IR2
402 ;;; translation when it determines whether a result temporary needs to
403 ;;; be made, and by representation selection when it is deciding which
404 ;;; move VOP to use. LVAR and TN are used to test for constant
406 (defun operand-restriction-ok (restr type
&key lvar tn
(t-ok t
))
407 (declare (type (or (member *) cons
) restr
)
408 (type primitive-type type
)
409 (type (or lvar null
) lvar
)
410 (type (or tn null
) tn
))
415 (dolist (mem (rest restr
) nil
)
416 (when (or (and t-ok
(eq mem
*backend-t-primitive-type
*))
421 (and (constant-lvar-p lvar
)
422 (funcall (second restr
) (lvar-value lvar
))))
424 (and (eq (tn-kind tn
) :constant
)
425 (funcall (second restr
) (tn-value tn
))))
427 (error "Neither LVAR nor TN supplied.")))))))
429 ;;; Check that the argument type restriction for TEMPLATE are
430 ;;; satisfied in call. If an argument's TYPE-CHECK is :NO-CHECK and
431 ;;; our policy is safe, then only :SAFE templates are OK.
432 (defun template-args-ok (template call safe-p
)
433 (declare (type template template
)
434 (type combination call
))
435 (let ((mtype (template-more-args-type template
)))
436 (do ((args (basic-combination-args call
) (cdr args
))
437 (types (template-arg-types template
) (cdr types
)))
439 (cond ((null args
) t
)
443 (unless (operand-restriction-ok mtype
446 (when (null args
) (return nil
))
447 (let ((arg (car args
))
449 (unless (operand-restriction-ok type
(lvar-ptype arg
)
453 ;;; Check that TEMPLATE can be used with the specifed RESULT-TYPE.
454 ;;; Result type checking is pretty different from argument type
455 ;;; checking due to the relaxed rules for values count. We succeed if
456 ;;; for each required result, there is a positional restriction on the
457 ;;; value that is at least as good. If we run out of result types
458 ;;; before we run out of restrictions, then we only succeed if the
459 ;;; leftover restrictions are *. If we run out of restrictions before
460 ;;; we run out of result types, then we always win.
461 (defun template-results-ok (template result-type
)
462 (declare (type template template
)
463 (type ctype result-type
))
464 (when (template-more-results-type template
)
465 (error "~S has :MORE results with :TRANSLATE." (template-name template
)))
466 (let ((types (template-result-types template
)))
468 ((values-type-p result-type
)
469 (do ((ltypes (append (args-type-required result-type
)
470 (args-type-optional result-type
))
472 (types types
(rest types
)))
474 (dolist (type types t
)
477 (when (null types
) (return t
))
478 (let ((type (first types
)))
479 (unless (operand-restriction-ok type
480 (primitive-type (first ltypes
)))
483 (operand-restriction-ok (first types
) (primitive-type result-type
)))
486 ;;; Return true if CALL is an ok use of TEMPLATE according to SAFE-P.
487 ;;; -- If the template has a GUARD that isn't true, then we ignore the
488 ;;; template, not even considering it to be rejected.
489 ;;; -- If the argument type restrictions aren't satisfied, then we
490 ;;; reject the template.
491 ;;; -- If the template is :CONDITIONAL, then we accept it only when the
492 ;;; destination of the value is an immediately following IF node.
493 ;;; -- If either the template is safe or the policy is unsafe (i.e. we
494 ;;; can believe output assertions), then we test against the
495 ;;; intersection of the node derived type and the lvar
496 ;;; asserted type. Otherwise, we just use the node type. If
497 ;;; TYPE-CHECK is null, there is no point in doing the intersection,
498 ;;; since the node type must be a subtype of the assertion.
500 ;;; If the template is *not* ok, then the second value is a keyword
501 ;;; indicating which aspect failed.
502 (defun is-ok-template-use (template call safe-p
)
503 (declare (type template template
) (type combination call
))
504 (let* ((guard (template-guard template
))
505 (lvar (node-lvar call
))
506 (dtype (node-derived-type call
)))
507 (cond ((and guard
(not (funcall guard
)))
509 ((not (template-args-ok template call safe-p
))
511 (if (and safe-p
(template-args-ok template call nil
))
514 ((eq (template-result-types template
) :conditional
)
515 (let ((dest (lvar-dest lvar
)))
517 (immediately-used-p (if-test dest
) call
))
519 (values nil
:conditional
))))
520 ((template-results-ok template dtype
)
523 (values nil
:result-types
)))))
525 ;;; Use operand type information to choose a template from the list
526 ;;; TEMPLATES for a known CALL. We return three values:
527 ;;; 1. The template we found.
528 ;;; 2. Some template that we rejected due to unsatisfied type restrictions, or
530 ;;; 3. The tail of Templates for templates we haven't examined yet.
532 ;;; We just call IS-OK-TEMPLATE-USE until it returns true.
533 (defun find-template (templates call safe-p
)
534 (declare (list templates
) (type combination call
))
535 (do ((templates templates
(rest templates
))
538 (values nil rejected nil
))
539 (let ((template (first templates
)))
540 (when (is-ok-template-use template call safe-p
)
541 (return (values template rejected
(rest templates
))))
542 (setq rejected template
))))
544 ;;; Given a partially annotated known call and a translation policy,
545 ;;; return the appropriate template, or NIL if none can be found. We
546 ;;; scan the templates (ordered by increasing cost) looking for a
547 ;;; template whose restrictions are satisfied and that has our policy.
549 ;;; If we find a template that doesn't have our policy, but has a
550 ;;; legal alternate policy, then we also record that to return as a
551 ;;; last resort. If our policy is safe, then only safe policies are
552 ;;; O.K., otherwise anything goes.
554 ;;; If we find a template with :SAFE policy, then we return it, or any
555 ;;; cheaper fallback template. The theory behind this is that if it is
556 ;;; cheapest, small and safe, we can't lose. If it is not cheapest,
557 ;;; then we use the fallback, which won't have the desired policy, but
558 ;;; :SAFE isn't desired either, so we might as well go with the
559 ;;; cheaper one. The main reason for doing this is to make sure that
560 ;;; cheap safe templates are used when they apply and the current
561 ;;; policy is something else. This is useful because :SAFE has the
562 ;;; additional semantics of implicit argument type checking, so we may
563 ;;; be forced to define a template with :SAFE policy when it is really
564 ;;; small and fast as well.
565 (defun find-template-for-ltn-policy (call ltn-policy
)
566 (declare (type combination call
)
567 (type ltn-policy ltn-policy
))
568 (let ((safe-p (ltn-policy-safe-p ltn-policy
))
569 (current (fun-info-templates (basic-combination-kind call
)))
573 (multiple-value-bind (template this-reject more
)
574 (find-template current call safe-p
)
576 (setq rejected this-reject
))
579 (return (values fallback rejected
)))
580 (let ((tcpolicy (template-ltn-policy template
)))
581 (cond ((eq tcpolicy ltn-policy
)
582 (return (values template rejected
)))
584 (return (values (or fallback template
) rejected
)))
585 ((or (not safe-p
) (eq tcpolicy
:fast-safe
))
587 (setq fallback template
)))))))))
589 (defvar *efficiency-note-limit
* 2
591 "This is the maximum number of possible optimization alternatives will be
592 mentioned in a particular efficiency note. NIL means no limit.")
593 (declaim (type (or index null
) *efficiency-note-limit
*))
595 (defvar *efficiency-note-cost-threshold
* 5
597 "This is the minumum cost difference between the chosen implementation and
598 the next alternative that justifies an efficiency note.")
599 (declaim (type index
*efficiency-note-cost-threshold
*))
601 ;;; This function is called by NOTE-REJECTED-TEMPLATES when it can't
602 ;;; figure out any reason why TEMPLATE was rejected. Users should
603 ;;; never see these messages, but they can happen in situations where
604 ;;; the VM definition is messed up somehow.
605 (defun strange-template-failure (template call ltn-policy frob
)
606 (declare (type template template
) (type combination call
)
607 (type ltn-policy ltn-policy
) (type function frob
))
608 (funcall frob
"This shouldn't happen! Bug?")
609 (multiple-value-bind (win why
)
610 (is-ok-template-use template call
(ltn-policy-safe-p ltn-policy
))
614 (funcall frob
"template guard failed"))
616 (funcall frob
"The template isn't safe, yet we were counting on it."))
618 (funcall frob
"argument types invalid")
619 (funcall frob
"argument primitive types:~% ~S"
623 (combination-args call
)))
624 (funcall frob
"argument type assertions:~% ~S"
629 (:or
`(:or .
,(mapcar #'primitive-type-name
631 (:constant
`(:constant
,(third x
))))))
632 (template-arg-types template
))))
634 (funcall frob
"conditional in a non-conditional context"))
636 (funcall frob
"result types invalid")))))
638 ;;; This function emits efficiency notes describing all of the
639 ;;; templates better (faster) than TEMPLATE that we might have been
640 ;;; able to use if there were better type declarations. Template is
641 ;;; null when we didn't find any template, and thus must do a full
644 ;;; In order to be worth complaining about, a template must:
645 ;;; -- be allowed by its guard,
646 ;;; -- be safe if the current policy is safe,
647 ;;; -- have argument/result type restrictions consistent with the
648 ;;; known type information, e.g. we don't consider float templates
649 ;;; when an operand is known to be an integer,
650 ;;; -- be disallowed by the stricter operand subtype test (which
651 ;;; resembles, but is not identical to the test done by
654 ;;; Note that there may not be any possibly applicable templates,
655 ;;; since we are called whenever any template is rejected. That
656 ;;; template might have the wrong policy or be inconsistent with the
659 ;;; We go to some trouble to make the whole multi-line output into a
660 ;;; single call to COMPILER-NOTIFY so that repeat messages are
662 (defun note-rejected-templates (call ltn-policy template
)
663 (declare (type combination call
) (type ltn-policy ltn-policy
)
664 (type (or template null
) template
))
667 (let ((safe-p (ltn-policy-safe-p ltn-policy
))
668 (verbose-p (policy call
(= inhibit-warnings
0)))
669 (max-cost (- (template-cost
671 (template-or-lose 'call-named
)))
672 *efficiency-note-cost-threshold
*)))
673 (dolist (try (fun-info-templates (basic-combination-kind call
)))
674 (when (> (template-cost try
) max-cost
) (return)) ; FIXME: UNLESS'd be cleaner.
675 (let ((guard (template-guard try
)))
676 (when (and (or (not guard
) (funcall guard
))
678 (ltn-policy-safe-p (template-ltn-policy try
)))
679 ;; :SAFE is also considered to be :SMALL-SAFE,
680 ;; while the template cost describes time cost;
681 ;; so the fact that (< (t-cost try) (t-cost
682 ;; template)) does not mean that TRY is better
683 (not (and (eq ltn-policy
:safe
)
684 (eq (template-ltn-policy try
) :fast-safe
)))
686 (and (template-note try
)
688 call
(template-type try
)
689 :argument-test
#'types-equal-or-intersect
691 #'values-types-equal-or-intersect
))))
697 (flet ((lose1 (string &rest stuff
)
700 (dolist (loser (losers))
701 (when (and *efficiency-note-limit
*
702 (>= (count) *efficiency-note-limit
*))
705 (let* ((type (template-type loser
))
706 (valid (valid-fun-use call type
))
707 (strict-valid (valid-fun-use call type
)))
708 (lose1 "unable to do ~A (cost ~W) because:"
709 (or (template-note loser
) (template-name loser
))
710 (template-cost loser
))
712 ((and valid strict-valid
)
713 (strange-template-failure loser call ltn-policy
#'lose1
))
715 (aver (not (valid-fun-use call type
717 :unwinnage-fun
#'lose1
))))
719 (aver (ltn-policy-safe-p ltn-policy
))
720 (lose1 "can't trust output type assertion under safe policy")))
723 (let ((*compiler-error-context
* call
))
724 (compiler-notify "~{~?~^~&~6T~}"
726 `("forced to do ~A (cost ~W)"
727 (,(or (template-note template
)
728 (template-name template
))
729 ,(template-cost template
))
731 `("forced to do full call"
736 ;;; If a function has a special-case annotation method use that,
737 ;;; otherwise annotate the argument lvars and try to find a template
738 ;;; corresponding to the type signature. If there is none, convert a
740 (defun ltn-analyze-known-call (call)
741 (declare (type combination call
))
742 (let ((ltn-policy (node-ltn-policy call
))
743 (method (fun-info-ltn-annotate (basic-combination-kind call
)))
744 (args (basic-combination-args call
)))
746 (funcall method call ltn-policy
)
747 (return-from ltn-analyze-known-call
(values)))
750 (setf (lvar-info arg
)
751 (make-ir2-lvar (primitive-type (lvar-type arg
)))))
753 (multiple-value-bind (template rejected
)
754 (find-template-for-ltn-policy call ltn-policy
)
755 ;; If we are unable to use some templates due to unsatisfied
756 ;; operand type restrictions and our policy enables efficiency
757 ;; notes, then we call NOTE-REJECTED-TEMPLATES.
759 (policy call
(> speed inhibit-warnings
)))
760 (note-rejected-templates call ltn-policy template
))
761 ;; If we are forced to do a full call, we check to see whether
762 ;; the function called is the same as the current function. If
763 ;; so, we give a warning, as this is probably a botched attempt
764 ;; to implement an out-of-line version in terms of inline
765 ;; transforms or VOPs or whatever.
767 (when (let ((funleaf (physenv-lambda (node-physenv call
))))
768 (and (leaf-has-source-name-p funleaf
)
769 (eq (lvar-fun-name (combination-fun call
))
770 (leaf-source-name funleaf
))
771 (let ((info (basic-combination-kind call
)))
772 (not (or (fun-info-ir2-convert info
)
773 (ir1-attributep (fun-info-attributes info
)
775 (let ((*compiler-error-context
* call
))
776 (compiler-warn "~@<recursion in known function definition~2I ~
777 ~_policy=~S ~_arg types=~S~:>"
778 (lexenv-policy (node-lexenv call
))
779 (mapcar (lambda (arg)
780 (type-specifier (lvar-type arg
)))
782 (ltn-default-call call
)
783 (return-from ltn-analyze-known-call
(values)))
784 (setf (basic-combination-info call
) template
)
785 (setf (node-tail-p call
) nil
)
788 (annotate-1-value-lvar arg
))))
792 ;;; CASTs are merely lvar annotations than nodes. So we wait until
793 ;;; value consumer deside how values should be passed, and after that
794 ;;; we propagate this decision backwards through CAST chain. The
795 ;;; exception is a dangling CAST with a type check, which we process
797 (defun ltn-analyze-cast (cast)
798 (declare (type cast cast
))
799 (setf (node-tail-p cast
) nil
)
800 (when (and (cast-type-check cast
)
801 (not (node-lvar cast
)))
803 (bug "IR2 type checking of unused values in not implemented.")
807 (defun ltn-annotate-casts (lvar)
808 (declare (type lvar lvar
))
811 (ltn-annotate-cast node
))))
813 (defun ltn-annotate-cast (cast)
814 (declare (type cast
))
815 (let ((2lvar (lvar-info (node-lvar cast
)))
816 (value (cast-value cast
)))
819 (ecase (ir2-lvar-kind 2lvar
)
821 (annotate-unknown-values-lvar value
))
823 (let* ((count (length (ir2-lvar-locs 2lvar
)))
824 (ctype (lvar-derived-type value
)))
825 (multiple-value-bind (types rest
)
826 (values-type-types ctype
(specifier-type 'null
))
827 (annotate-fixed-values-lvar
829 (mapcar #'primitive-type
830 (adjust-list types count rest
))))))))
836 ;;; most of the guts of the two interface functions: Compute the
837 ;;; policy and dispatch to the appropriate node-specific function.
839 ;;; Note: we deliberately don't use the DO-NODES macro, since the
840 ;;; block can be split out from underneath us, and DO-NODES would scan
841 ;;; past the block end in that case.
842 (defun ltn-analyze-block (block)
843 (do* ((node (block-start-node block
)
845 (ctran (node-next node
) (node-next node
)))
850 (case (basic-combination-kind node
)
851 (:local
(ltn-analyze-local-call node
))
852 ((:full
:error
) (ltn-default-call node
))
854 (ltn-analyze-known-call node
))))
855 (cif (ltn-analyze-if node
))
856 (creturn (ltn-analyze-return node
))
858 (exit (ltn-analyze-exit node
))
859 (cset (ltn-analyze-set node
))
860 (cast (ltn-analyze-cast node
))
862 (ecase (basic-combination-kind node
)
864 (ltn-analyze-mv-bind node
))
866 (ltn-analyze-mv-call node
)))))
867 (when (eq node
(block-last block
))
870 ;;; Loop over the blocks in COMPONENT, doing stuff to nodes that
871 ;;; receive values. In addition to the stuff done by FROB, we also see
872 ;;; whether there are any unknown values receivers, making notations
873 ;;; in the components' GENERATORS and RECEIVERS as appropriate.
875 ;;; If any unknown-values lvars are received by this block (as
876 ;;; indicated by IR2-BLOCK-POPPED), then we add the block to the
877 ;;; IR2-COMPONENT-VALUES-RECEIVERS.
879 ;;; This is where we allocate IR2 blocks because it is the first place
881 (defun ltn-analyze (component)
882 (declare (type component component
))
883 (let ((2comp (component-info component
)))
884 (do-blocks (block component
)
885 (aver (not (block-info block
)))
886 (let ((2block (make-ir2-block block
)))
887 (setf (block-info block
) 2block
)
888 (ltn-analyze-block block
)))
889 (do-blocks (block component
)
890 (let ((2block (block-info block
)))
891 (let ((popped (ir2-block-popped 2block
)))
893 (push block
(ir2-component-values-receivers 2comp
)))))))
896 ;;; This function is used to analyze blocks that must be added to the
897 ;;; flow graph after the normal LTN phase runs. Such code is
898 ;;; constrained not to use weird unknown values (and probably in lots
900 (defun ltn-analyze-belated-block (block)
901 (declare (type cblock block
))
902 (ltn-analyze-block block
)
903 (aver (not (ir2-block-popped (block-info block
))))